JP2023536030A - cutting blades and hair removal devices - Google Patents

Abstract

The present invention provides a first surface (2), a second surface (3) opposite the first surface, and a cutting edge (4) at the intersection of the first surface and the second surface. The present invention relates to a cutting blade (1) having the following. The first surface comprises a first surface (9) and a primary slope (7), and the first wedge angle (θ1) is the angle between the first surface and the primary slope. The second surface includes a secondary slope (5) and a tertiary slope (6), and a second wedge angle (θ2) is defined between the first surface and the secondary slope on the first surface. The third wedge angle (θ3) is the angle between the first surface on the first surface and the tertiary slope. Furthermore, the present invention relates to a hair removal device equipped with this cutting blade.

Description

The present invention relates to a cutting blade having a first face, a second face opposite the first face, and a cutting edge at the intersection of the first face and the second face. The first face comprises a first surface and a primary oblique surface, and the first wedge angle θ ₁ is the angle between the first surface and the primary oblique surface. The second face comprises a secondary bevel and a tertiary bevel, a second wedge angle _θ2 is the angle between the first surface and the secondary bevel on the first face, and a third The wedge angle θ ₃ is the angle between the first surface and the tertiary slope on the first surface. Furthermore, the invention relates to an epilation device comprising this cutting blade.

The following definitions are used in this application.
• The rake face is the surface of the cutting blade on which the cut hairs that are removed in the cutting process slide.
• The removal surface is the surface of the cutting tool that passes over the skin. The angle between the removal surface and the contact surface is the removal angle α.
• The cutting bevel of the cutting blade is bounded by the rake face and the removal face and is denoted by bevel angle θ.
• The cutting edge is the line of intersection of the rake face and the removal face.

Cutting blades, especially razor blades, are typically made from a suitable substrate material, such as stainless steel, which forms a symmetrical wedge-shaped cutting edge.

With respect to razor blades, the cutting blade design must be optimized to find the best compromise between blade sharpness and mechanical strength and thus durability of the cutting edge. The manufacture of conventional stainless steel razor blades typically involves hardening the steel substrate before the blade is sharpened from both sides to form a symmetrical cutting edge by grinding the hardened steel substrate. .

Further coatings can be applied to the steel blade after sharpening in order to optimize the mechanical properties of the blade. Hard coating materials such as diamond, amorphous diamond, diamond-like carbon (DLC), nitrides, carbides or oxides are suitable for improving the mechanical strength of the cut edge.

Therefore, harder cutting edge materials are expected to have longer edge retention efficacy, resulting in less wear. Other coatings may be applied to increase corrosion resistance or reduce blade friction.

Most prior art blades focus on blades with symmetrical blade bodies. However, there are some approaches in which blades with asymmetrical blades are taught.

U.S. Pat. No. 3,606,682 describes a razor blade with improved ease of cutting and improved shaving comfort. The blade has a recess adjacent the cutting edge, which allows for improved shaving comfort. This effect has been demonstrated with symmetrical and asymmetrical blade bodies.

U.S. Pat. No. 3,292,478 describes a method for cutting textiles, leather and the like wherein the knife preferably has slanted surfaces on both sides so that the cutting edge is not centered between the sides and the knife has an asymmetrical shape. A cutting die knife for sheet material is described.

There is a continuing desire to cut objects as close as possible to the surface while reducing or avoiding the risk of cutting the surface itself. In shaving situations, cutting hairs close to the skin without damaging the skin is desirable to meet the requirements of accurate and safe shaving.

U.S. Pat. No. 3,606,682 U.S. Pat. No. 3,292,478

The present invention therefore addresses the mentioned drawbacks in the prior art and provides a cutting blade design that simultaneously allows good proximity to the surface on which the object is to be cut and a high degree of safety to avoid cutting the surface. I will provide a.

This problem is solved by a cutting blade with the features of claim 1 and an epilation device with the features of claim 16 . Further dependent claims define preferred embodiments of such blades.

The term "comprising" in the claims and description of the application means that further components are not excluded. Within the scope of the present invention, the term "consisting of" is to be understood as a preferred embodiment of the term "comprising". Where a group is defined as "comprising" at least a specified number of members, this should also be understood to preferably disclose a group "consisting of" these members.

In the following, the term cross section refers to a cross section perpendicular to the linear extension of the cutting edge (if the cutting edge is straight) or to the tangent to the cutting edge (if the cutting edge is curved). Point.

The term intersection should be understood as a linear extension (in cross-section in FIG. 3) of the intersection between different slopes in perspective (in FIG. 1). As an example, if the straight slopes are adjacent to each other, the intersection point in the cross-sectional view expands to the intersection line in the perspective view.

According to the present invention, a cutting blade is provided having a first surface, a second surface opposite the first surface and different from the first surface, and a cutting edge,
- the first face comprises a first surface and a primary slope;
- the primary bevel extends from the cutting edge to the first surface;
- a first intersection line connects the primary slope and the first surface;
the first wedge angle θ ₁ is the angle between the imaginary extension (9′) of the first surface and the primary slope;
- the second surface comprises a secondary slope and a tertiary slope;
- the secondary bevel extends from the cut edge to the tertiary bevel;
- a second intersection line connects the secondary and tertiary slopes;
the second wedge angle θ ₂ is the angle between the first surface and the secondary slope;
• The third wedge angle _θ3 is the angle between the first surface and the tertiary slope.

Surprisingly, between proximity and safety to the surface being cut while having a very stable cutting edge with very good cutting performance when the wedge angle satisfies the following conditions: It has been found that cutting blades can be provided that achieve the best compromise:
θ ₁ >θ ₂ and θ ₂ <θ ₃ .

Cutting blades according to the present invention have low cutting forces due to thin secondary bevels with low wedge angles.

A cutting edge according to the present invention is strengthened by adding a primary bevel having a first wedge angle greater than a second wedge angle. Thus, the primary bevel with the first wedge angle θ ₁ has the function of mechanically stabilizing the cutting edge against damage from the cutting action, thereby affecting the cutting performance of the blade. but allows for a slim blade body in the region of the secondary bevel. Furthermore, the primary bevel with wedge angle θ ₁ allows the cutting edge to be lifted from the surface, reducing the risk of damaging the surface and thereby increasing the safety of the cutting operation.

Therefore, the primary bevel with the first wedge angle θ ₁ has the function of stabilizing the angle of the cutting edge to prevent damage to the cutting edge when the object is being cut, i.e. the larger wedge The angle θ ₁ increases the mechanical stability of the cutting edge. As a result, the secondary wedge angle θ ₂ can be reduced by using a primary bevel with wedge angle θ ₁ .

The wedge angle θ ₁ has the function of stabilizing the cutting edge without affecting the cutting performance of the blade, thereby allowing a slim blade body in the region of the secondary bevel. In addition, the primary bevel with wedge angle θ ₁ allows the cutting edge to be lifted from the object being cut, making the cutting process safer, e.g. Cutting the skin can be avoided by increasing the distance of .

The second wedge angle θ ₂ represents the penetration angle of the blade through the object being cut. The smaller the penetration angle _θ2 , the smaller the force that penetrates the object being cut.

A cutting blade according to the present invention adds a thick, strong tertiary bevel with a third wedge angle that is greater than the second wedge angle, which is used to divide the object to be cut into two thin two halves. It is further enhanced by reducing the forces acting on the sub-slope.

The third wedge angle _θ3 represents the splitting angle, ie the angle required to split the object being cut. For this function, the third wedge angle _θ3 must be greater than the second wedge angle _θ2 .

According to a preferred embodiment, the cutting blade has an asymmetrical cross-sectional shape. Asymmetric cross-sectional shape refers to symmetry about an axis fixed to the cutting edge, which is the bisector of the second wedge angle θ ₂ .

According to a preferred embodiment, the first wedge angle θ ₁ ranges from 5 degrees to 75 degrees, preferably from 10 degrees to 60 degrees, more preferably from 15 degrees to 46 degrees, even more preferably from 20 degrees to 45 degrees. and/or the second wedge angle θ ₂ is in the range of -5 degrees to 40 degrees, preferably 0 degrees to 30 degrees, more preferably 5 degrees to 25 degrees, even more preferably 10 degrees to 15 degrees and/or the third wedge angle θ ₃ is in the range of 1 degree to 60 degrees, preferably 10 degrees to 55 degrees, more preferably 19 degrees to 46 degrees, most preferably 45 degrees, Even more preferably, it is in the range of 20 degrees to 45 degrees.

According to a further preferred embodiment, the primary bevel has a length _d1 , the dimension from the cutting edge to the first intersection line and projected onto the imaginary extension of the first surface. , the length d ₁ is 0.1 to 7 μm, preferably 0.5 to 5 μm, more preferably 1 to 3 μm. A length d ₁ of less than 0.1 μm is too fragile to be produced and does not allow stable use of the cutting blade. Surprisingly, it has been found that the primary bevel stabilizes the blade body at the secondary and tertiary bevels, thereby allowing a slim blade in the region of the secondary bevel providing low cutting forces. . On the other hand, if the length _d1 is 7 μm or less, the primary slope does not affect the cutting performance.

Preferably dimensioned from the cut edge to the second intersecting edge and projected onto the first surface and/or an imaginary extension of the first surface (i.e. projection of primary and secondary oblique surfaces) The dimension length d ₂ ranges from 1 to 150 μm, more preferably from 5 to 100 μm, even more preferably from 10 to 75 μm, especially from 15 to 50 μm. The length _d2 corresponds to the depth of penetration of the cutting blade into the object to be cut. Generally, _d2 corresponds to at least 30% of the diameter of the object to be cut, i.e. when the object is a human hair typically having a diameter of about 100 μm, the length _d2 is about 30 μm. be.

The cutting blade is preferably defined by a blade body comprising or consisting of a first material and a second material joined to the first material. The second material can be deposited as a coating on at least the region of the first material, i.e. the second material is an over coating of the first material or a coating of the first material on the first surface. It can be a deposited coating.

The material of the first material is generally not limited to any particular material as long as it is possible to grade this material.

However, according to an alternative embodiment, the blade body consists only of the first material, i.e. the uncoated first material. In this case, the first material is preferably a material with an isotropic structure, ie with identical property values in all directions. Such isotropic materials are often more suitable for molding, regardless of the molding technique.

The first material is
metals, preferably titanium, nickel, chromium, niobium, tungsten, tantalum, molybdenum, vanadium, platinum, germanium, iron and alloys thereof, especially steel,
- carbon, nitrogen, boron, oxygen and combinations thereof, preferably selected from the group consisting of silicon carbide, zirconium oxide, aluminum oxide, silicon nitride, boron nitride, tantalum nitride, TiAlN, TiCN and/or _TiB2 a ceramic comprising at least one element,
a glass-ceramic, preferably an aluminum-containing glass-ceramic,
- Composite materials made from ceramic materials in a metal matrix (cermet),
- hard metals, preferably cemented carbide hard metals such as tungsten carbide or titanium carbide combined with cobalt or nickel;
- preferably silicon or germanium with crystal planes parallel to the second plane and wafer orientation <100>, <110>, <111> or <211>;
・Single crystal materials,
- glass or sapphire,
- polycrystalline or amorphous silicon or germanium,
- single crystal or polycrystalline diamond, diamond-like carbon (DLC), adamantane carbon, and - combinations thereof,
comprising or consisting of a material selected from the group consisting of

The steel used for the first material is preferably 1095, 12C27, 14C28N, 154CM, 3Cr13MoV, 4034, 40X10C2M, 4116, 420, 440A, 440B, 440C, 5160, 5Cr15MoV, 8Cr13MoV, 95X18, 9Cr18MoV, A cuto+, ATS-34, AUS-4, AUS-6 (=6A), AUS-8 (=8A), C75, CPM-10V, CPM-3V, CPM-D2, CPM-M4, CPM-S-30V, CPM- S-35VN, CPM-S-60V, CPM-154, Cronidur-30, CTS204P, CTS20CP, CTS40CP, CTSB52, CTSB75P, CTSBD-1, CTSBD-30P, CTSXHP, D2, Elmax, GIN-1, H1, N690, N695, Niolox (1.4153), Nitro-B, S70, SGPS, SK-5, Sleipner, T6MoV, VG-10, VG-2, X-15T. N. , X50CrMoV15, ZDP-189.

Preferably, the second material is
- oxides, nitrides, carbides, borides, preferably aluminum nitride, chromium nitride, titanium nitride, titanium nitride carbon, titanium aluminum nitride, cubic boron nitride,
Boron Aluminum Magnesium,
- carbon, preferably diamond, polycrystalline diamond, nanocrystalline diamond, diamond-like carbon (DLC), and - combinations thereof,
comprising or consisting of a material selected from the group consisting of

The second material may preferably be selected from the group consisting of _TiB2 , AlTiN, TiAlN, TiAlSiN, TiSiN, CrAl, CrAlN, AlCrN, CrN, TiN, TiCN, and combinations thereof.

Additionally, all materials cited in the VDI guidelines 2840 can be selected for the second material.

It is particularly preferred to use a multilayered second material of nanocrystalline diamond and/or nanocrystalline and polycrystalline diamond as the second material. With respect to single crystal diamond, it has been demonstrated that compared to the production of single crystal diamond, the production of nanocrystalline diamond can be achieved substantially more easily and economically. Therefore, longer and larger area cutting blades can also be provided. Furthermore, with respect to their grain size distribution, nanocrystalline diamond layers are more homogeneous than polycrystalline diamond layers, and the materials also exhibit lower intrinsic stresses. As a result, macroscopic distortion of the cut edge is less likely.

The second material preferably has a thickness of 0.15-20 μm, preferably 2-15 μm, more preferably 3-12 μm.

Preferably, the second material has a modulus of elasticity (Young's modulus) of less than 1200 GPa, preferably less than 900, more preferably less than 750 GPa. The low modulus of elasticity makes the hard coating more flexible and more elastic, allowing it to conform better to the substrate, object, or contour being cut. Young's modulus was determined by Ma, kus Mohr et al. "Youngs modulus, fracture strength, and Poisson's ratio of nanocrystalline diamond films", J. Am. Appl. Phys. 116, 124308 (2014), especially paragraph III. B. Determined according to the method disclosed in Static measurements of Young's modulus.

The second material preferably has a transverse breaking stress σ ₀ of at least 1 GPa, more preferably at least 2.5 GPa, even more preferably at least 5 GPa.

For a definition of the transverse breaking stress σ ₀ see the following references.
・R. Morrell et al. , Int. Journal of Refractory Metals & Hard Materials, 28 (2010), p. 508-515;
・R. Danzer et al. Published by "Technische keramische Werkstoffe", HvB Press, Ellerau, ISBN 978-3-938595-00-8, chapter 6.2.3.1 "Der 4-Kugelversuch zur Ermittlung der biaxialen Bie gefestigkeit sporoder Werkstoffe"

Thereby, the transverse breaking stress σ ₀ is determined by statistical evaluation of a destructive test, for example a B3B load test according to the details of the above mentioned literature. Thus, it is defined as a breaking stress with a probability of breaking of 63%.

Due to the very high transverse breaking stress of the second material, detachment of individual crystals from the second material, especially from the cut edge, is almost completely suppressed. Even with long-term use, the cutting blade retains its original sharpness.

The second material preferably has a hardness of at least 20 GPa. Hardness is determined by nanoindentation (Yeon-Gil Jung et. al., J. Mater. Res., Vol. 19, No. 10, p. 3076).

The second material preferably has a surface roughness R _RMS of less than 100 nm RMS, more preferably less than 50 nm, even more preferably less than 20 nm, calculated by the formula:

Ａ＝評価面積
Ｚ（ｘ、ｙ）＝局所粗さ分布

A = evaluation area Z (x, y) = local roughness distribution

The surface roughness R _RMS is according to DIN EN ISO25178. determined according to The aforementioned surface roughness obviates the need for additional mechanical polishing of the grown second material.

In a preferred embodiment, the second material has an average nanocrystalline diamond particle size d ₅₀ of 1-100 nm, preferably 5-90 nm, more preferably 7-30 nm, even more preferably 10-20 nm. The average particle size _d50 can be determined using X-ray diffraction or transmission electron microscopy and particle counting.

The first material and/or the second material are at least preferably fluoropolymers (e.g., PTFE), parylene, polyvinylpyrrolidone, polyethylene, polypropylene, polymethylmethacrylate, graphite, diamond-like carbon (DLC), and their It is preferably coated with regions having a low friction material selected from the group consisting of combinations.

The lines intersecting the primary and secondary bevels are preferably molded into the second material.

More preferably, the line between the second bevel and the tertiary bevel is located at the interface between the first and second materials to make the manufacturing process easier to handle and therefore more economical. Yes, for example, the blade can be manufactured according to the process of Figures 7a-d.

The cutting edge ideally has a rounded configuration that improves blade stability. The cutting edge preferably has a tip radius of less than 200 nm, more preferably less than 100 nm, even more preferably less than 50 nm, determined by cross-sectional SEM using, for example, the method shown in FIG.

The tip radius r of the cutting edge is preferably correlated with the average grain size _d50 of the hard coating. The ratio r/ _d50 between the rounding radius r of the nanocrystalline diamond as the second material at the cut edge and the average grain size d50 of the nanocrystalline diamond as the second material is between 0.03 and 20, preferably It is advantageously between 0.05 and 15, particularly preferably between 0.5 and 10.

In a further preferred embodiment, the secondary beveled surface comprises a further beveled region, the beveled region extending from the cut edge to a third intersection line connecting the secondary beveled surface and the beveled region, the beveled region comprising: Preferably there is a fourth wedge angle _θ4 between the first surface and the angled region.

Preferably, the first surface corresponds to the removal surface and the second surface corresponds to the rake surface of the cutting blade.

Therefore, according to the invention there is also provided an epilation device comprising a razor blade as described above.

The invention is further illustrated by the following figures which show specific embodiments according to the invention. These specific embodiments, however, should not be construed in any limiting manner with respect to the present invention, as set forth in the claims in the general part of this specification.
1 is a schematic view of a cutting blade according to the invention; FIG. 1 is a cross-sectional view of a cutting blade according to the invention; FIG. Fig. 3 is another cross-sectional view of a cutting blade according to the invention with a second material; FIG. 10 is a cross-sectional view of another cutting blade according to the invention with an additional beveled area of the secondary bevel; FIG. 10 is a cross-sectional view of another cutting blade according to the invention with an additional sloped area of the secondary bevel of the second material; 1 is a perspective view of a first cutting blade according to the present invention having a non-straight cutting edge with curved portions; FIG. 4 is a flow chart of a process for manufacturing a cutting blade; 4 is a flow chart of a process for manufacturing a cutting blade; 4 is a flow chart of a process for manufacturing a cutting blade; 4 is a flow chart of a process for manufacturing a cutting blade; FIG. 10 is a schematic cross-sectional view of a rounded tip showing determination of tip radius;

The following reference numerals are used in the drawings of this application.

LIST OF REFERENCE NUMBERS 1 blade 2 first face 3 second face 4 cutting edge 5 secondary bevel 6 tertiary bevel 7 primary bevel 9 first surface 9' imaginary extension of first surface 11 second intersection line 12 first intersection line 15 blade body 18 first material 19 second material 20 interface 60 bisector 61 vertical line 62 circle 65 construction point 66 construction point 67 construction point 260 bisector

1 is a perspective view of a cutting blade according to the invention; FIG. This cutting blade 1 has a blade body 15 with a first face 2 and a second face 3 opposite the first face 2 . A cutting edge 4 is located at the intersection of the first plane 2 and the second plane 3 . The cutting edge 4 is straight or substantially straight. The first face 2 comprises a planar first surface 9 and a primary bevel 7, while the second face 3 is segmented into two bevels. The second face 3 comprises a secondary slope 5 and a tertiary slope 6 . The primary bevel 7 is connected to the first surface 9 via a first intersection line 12 . The secondary slope 5 is connected to the tertiary slope 6 via a second intersection line 11 .

2 is a cross-sectional view of the cutting blade of FIG. 1; FIG. The first face 2 comprises a planar first surface 9 and primary slopes 7 connected by a first intersection line 12 . The primary bevel 7 has a first wedge angle θ ₁ between the imaginary extension 9' of the first surface and the primary bevel 7, while the second face 3 is divided into two bevels, i.e. secondary Beveled surface 5 has a second wedge angle θ ₂ between first surface 9 and secondary beveled surface 5 and bisector 260 bisects second wedge angle θ ₂ . The tertiary bevel 6 has a third wedge angle θ ₃ between the first surface 9 and the tertiary bevel 6 that is greater than θ ₂ . The tertiary slope 6 has a third wedge angle θ ₃ greater than θ ₂ . The primary bevel 7 has a length d ₁ , the dimension projected onto the imaginary extension 9' of the first surface, in the range 0.1-7 μm. The secondary bevel 5 has a length _d2 , the dimension projected onto the first surface 9 and the imaginary extension 9' of the first surface, in the range 1-150 μm.

FIG. 3 is another cross-sectional view of the cutting blade of the present invention, corresponding primarily to the embodiment of FIG. The main difference is that the blade body 15 comprises a first material 18 and a second material 19 bonded to the first material 18, the first material 18 being for example silicon and the second material 19 is, for example, a diamond layer. The primary bevel 7 and the secondary bevel 5 are located on the second material 19 , while the tertiary bevel 6 is located on the first material 18 . The first material 18 and the second material 19 are separated by an interface terminating at the second intersection line 11 .

FIG. 4 is a cross-sectional view of another cutting blade according to the invention; The cutting blade 1 has a blade body with a first face 2 and a second face 3 opposite the first face 2 . The first face 2 comprises a first surface 9 and a primary slope 7 having a length _d1 . The second face 3 comprises a secondary slope 5 and a tertiary slope 6 . The secondary slope 5 is connected to the tertiary slope 6 via a second intersection line 11 . Furthermore, the second bevel 5 comprises a beveled area 8 extending from the second intersection line 11 to the cutting edge 4 . The cutting edge 4 is located at the intersection of the primary bevel 7 and the beveled area 8 of the secondary bevel 5 . The length d ₁ of the primary bevel 7 and the wedge angle θ ₁ define the distance between the cutting edge 4 and the object to be cut when the object to be cut lies on the first surface 2 .

FIG. 5 is another cross-sectional view of the cutting blade of the present invention, corresponding primarily to the embodiment of FIG. However, the embodiment of FIG. 4 has a blade body 15 that includes first material 18 and second material 19 . The primary bevel 7 , the secondary bevel 5 and the sloped area 8 are all located in the second material 19 while the tertiary bevel 6 is located in the first material 18 . The first material 18 and the second material 19 are joined along an interface 20 that terminates at the second intersecting edge 11 .

Figure 6 is a perspective view of another cutting blade according to the present invention; The cutting blade 1 has a blade body 15 with a first face 2 and a second face 3 opposite the first face 2 . A cutting edge 4 is located at the intersection of the first plane 2 and the second plane 3 . In this embodiment, the cutting edge 4 is not straight but shaped with a curved portion. The first side 2 comprises a planar first surface 9 and a primary bevel 7 and the second side 3 is divided into a secondary bevel 5 and a tertiary bevel 6 . The primary bevel 5 is connected to the first surface 9 via a first line of intersection 12 and the secondary bevel is connected to the tertiary bevel 7 via a second line of intersection 11 . The lines of intersection 11 and 12 follow the shape of the cutting edge 4 and are therefore not straight but of a shape comprising curved portions.

Figures 7a-7d show a flow chart of the process of the present invention. In a first step 1, a silicon wafer 101 is coated with a silicon nitride (Si ₃ N ₄ ) layer 102 as a protective layer of silicon by PE-CVD or thermal treatment (low pressure CVD). Layer thicknesses and deposition procedures must be carefully chosen to allow sufficient chemical stability to withstand the following etching steps. In step 2, a photoresist 103 is deposited on the _Si3N4 coated substrate and then patterned by photolithography. The (Si ₃ N ₄ ) layer is then structured, for example by CF ₄ plasma reactive ion etching (RIE) using the patterned photoresist as a mask. After patterning, in step 3, the photoresist 103 is stripped with an organic solvent. The remaining patterned Si ₃ N ₄ layer 102 serves as a mask for the following pre-structuring step 4 of the silicon wafer 101, for example by anisotropic wet chemical etching in KOH. The etching process ends when the structures on the second side 3 reach a predetermined depth and leave the first side 2 of continuous silicon. For example, isotropic wet chemical etching in HF/ _HNO3 solution or other wet chemical processes such as application of fluorine containing plasma may be suitable. In step 5 below, the remaining Si ₃ N ₄ is removed, for example by hydrofluoric acid (HF) or fluorine plasma treatment. In step 6, the pre-structured Si substrate is coated with a thin diamond layer 104 of about 10 μm, eg nanocrystalline diamond. The diamond layer 104 is on the second side 3 before structuring and on the continuous first side 2 of the Si-wafer 101 (shown in step 6) or on the continuous first side 2 of the Si wafer. (not shown here). In the case of double-sided coating, the diamond layer 104 on the structured second side 3 has to be removed in a further step 7 before the following edge forming steps 9-11 of the cutting blade. Selective removal of the diamond layer 104 is performed, for example, by using an Ar/O ₂ -plasma (eg RIE or ICP mode) which exhibits high selectivity to the silicon substrate. In step 8, the silicon wafer 101 is thinned so that the diamond layer 104 is partially free-standing without substrate material and the desired substrate thickness is achieved in the remaining areas. This step can be performed by wet chemical etching in KOH or HF/ _HNO3 etchants or plasma etching in _CF4 , _SF6 or _CHF3 containing plasma, preferably in RIE or ICP mode.

In the next step 9, the diamond film is anisotropically etched by Ar/O ₂ -plasma in a RIE system to form nearly vertical bevels 5' with 90 degree corners in the diamond layer 104, which are , as shown in step 10, is required to form the primary bevel 7 on the first face 2 of the cutting blade.

In order to form the primary bevel 7 on the first side 2 of the cutting blade, the Si-wafer 101 is now rotated to expose the first side 2 to the subsequent etching step 10 (FIG. 7b). The 90 degree corner 5' is chamfered to form the primary bevel 7 by utilizing a physically enriched anisotropic RIE process in an Ar/ _O2 plasma. Process details are disclosed in EP 2 727 880, for example.

Finally, in step 11 (Fig. 7c), the Si-wafer 101 on the second side 3 is treated to complete the cutting edge formation by forming secondary bevels 5, as shown in Fig. 7d. . Multiple slopes can be formed by varying process parameters. Process details are disclosed, for example, in DE 198 59 905 A1.

FIG. 8 shows how the tip radius can be determined. The tip radius is first determined by drawing a line 60 that bisects the cross-sectional image of the first bevel of cutting edge 1 . If line 60 bisects the first slope, point 65 is drawn. A second line 61 is drawn perpendicular to line 60 at a distance of 110 nm from point 65 . If line 61 bisects the first slope, two additional points 66 and 67 are drawn. A circle 62 is then constructed from points 65 , 66 and 67 . The radius of circle 62 is the tip radius of cutting edge 4 .

Claims (16)

a first surface (2), a second surface (3) facing said first surface (2), and an intersection of said first surface (2) and said second surface (3) A cutting edge (1) having a cutting edge (4) at
- said first face (2) comprises a first surface (9) and a primary slope (7);
- said primary bevel (7) extends from said cutting edge (4) to said first surface (9);
- a first intersection line (12) connects said primary slope (7) and said first surface (9);
the first wedge angle θ ₁ is the angle between the imaginary extension (9′) of said first surface and said primary slope (7);
- said second face (3) comprises a secondary slope (5) and a tertiary slope (6);
- said secondary bevel (5) extends from said cutting edge (4) to said tertiary bevel (6);
- a second intersection line (11) connects said secondary slope (5) and said tertiary slope (6);
- the second wedge angle _θ2 is the angle between said first surface (9) and said secondary slope (5);
- the third wedge angle θ ₃ is the angle between said first surface (9) and said tertiary slope (6);
A cutting edge where θ ₁ >θ ₂ and θ ₂ <θ ₃ . the first wedge angle θ ₁ ranges from 5 degrees to 75 degrees, preferably from 10 degrees to 60 degrees, more preferably from 15 degrees to 46 degrees, even more preferably from 20 degrees to 45 degrees, and/or The second wedge angle θ ₂ ranges from −5 degrees to 40 degrees, preferably from 0 degrees to 30 degrees, more preferably from 5 degrees to 25 degrees, and/or the third wedge angle θ ₃ ranges from , 1 degree to 60 degrees, preferably 10 degrees to 55 degrees, more preferably 19 degrees to 46 degrees, most preferably 45 degrees. Said primary bevel (7) is projected onto said imaginary extension (9') of said first surface, dimensioned from said cut edge (4) to said first intersection line (12). 1 or 2, characterized in that it has a length d ₁ which is a dimension, said length d ₁ being between 0.1 and 7 μm, preferably between 0.5 and 5 μm, more preferably between 1 and 3 μm. 3. The cutting blade according to any one of 2. on said first surface (9) and/or said imaginary extension (9') of said first surface in the dimension from said cutting edge (4) to said second line of intersection (11) 4. Any of claims 1-3, characterized in that the projected dimension has a length _d2 ranging from 1 to 150 μm, preferably from 5 to 100 μm, more preferably from 10 to 75 μm, especially from 15 to 50 μm. or the cutting blade according to item 1. Said cutting blade (1) comprises or consists of a blade body (15) made of a first material (18) or said cutting blade (1) comprises a first material (18) and said first material (18). 5. The blade body (15) according to any one of claims 1 to 4, characterized in that it comprises or consists of a blade body (15) comprising or consisting of a second material (19) joined to a material (18). The cutting blade described in . said first material (18) comprising:
metals, preferably titanium, nickel, chromium, niobium, tungsten, tantalum, molybdenum, vanadium, platinum, germanium, iron and alloys thereof, especially steel,
- carbon, nitrogen, boron, oxygen and combinations thereof, preferably selected from the group consisting of silicon carbide, zirconium oxide, aluminum oxide, silicon nitride, boron nitride, tantalum nitride, TiAlN, TiCN and/or _TiB2 a ceramic comprising at least one element,
a glass-ceramic, preferably an aluminum-containing glass-ceramic,
- Composite materials made from ceramic materials in a metal matrix (cermet),
- hard metals, preferably cemented carbide hard metals such as tungsten carbide or titanium carbide combined with cobalt or nickel;
- preferably silicon or germanium with a crystal plane parallel to said second face (2) and with a wafer orientation of <100>, <110>, <111> or <211>,
・Single crystal materials,
- glass or sapphire;
- polycrystalline or amorphous silicon or germanium,
- single crystal or polycrystalline diamond, diamond-like carbon (DLC), adamantane carbon, and - combinations thereof,
6. A cutting blade according to claim 5, characterized in that it comprises or consists of a material selected from the group consisting of: The material of said second material (19) is
- oxides, nitrides, carbides, borides, preferably aluminum nitride, chromium nitride, titanium nitride, titanium nitride carbon, titanium aluminum nitride, cubic boron nitride,
Boron Aluminum Magnesium,
- carbon, preferably diamond, polycrystalline diamond, nanocrystalline diamond, diamond-like carbon (DLC), and - combinations thereof,
7. A cutting blade according to claim 5 or 6, characterized in that it comprises or consists of a material selected from the group consisting of: Said second material (19) has the following properties:
a thickness of 0.15 to 20 μm, preferably 2 to 15 μm, more preferably 3 to 12 μm,
- a modulus of elasticity less than 1200 GPa, preferably less than 900 GPa, more preferably less than 750 GPa;
- a transverse breaking stress σ ₀ of at least 1 GPa, preferably at least 2.5 GPa, more preferably at least 5 GPa,
a hardness of at least 20 GPa;
The cutting blade according to any one of claims 5 to 7, characterized in that it satisfies at least one of The material of the second material (19) is nanocrystalline diamond and has the following properties:
- an average surface roughness R _RMS of less than 100 nm, less than 50 nm, more preferably less than 20 nm,
an average particle size d ₅₀ of the nanocrystalline diamond between 1 and 100 nm, preferably between 5 and 90 nm, more preferably between 7 and 30 nm, even more preferably between 10 and 20 nm,
The cutting blade according to any one of claims 5 to 8, characterized in that it satisfies at least one of said first material (18) and/or said second material (19) are at least preferably fluoropolymers, parylene, polyvinylpyrrolidone, polyethylene, polypropylene, polymethylmethacrylate, graphite, diamond-like carbon (DLC), A cutting blade according to any one of claims 5 to 9, characterized in that it is coated with a region having a low-friction material selected from the group consisting of and combinations thereof. A cutting blade according to any one of claims 5 to 10, characterized in that said first line of intersection (12) is molded into said second material (19). Claims 5 to 11, characterized in that said second line of intersection (11) is arranged at the interface (20) of said first material (18) and said second material (19). The cutting blade according to any one of . Cutting blade according to any one of the preceding claims, characterized in that said cutting edge (4) has a tip radius of less than 200 nm, preferably less than 100 nm, more preferably less than 50 nm. Said secondary bevel (5) comprises a further beveled area (8), said beveled area connecting said secondary bevel (5) and said beveled area (8) from said cutting edge (4). Extending to a third line of intersection (11), said slanted region (8) preferably defines a fourth wedge angle _θ4 between said first surface (9) and said slanted region (8). The cutting blade according to any one of claims 1 to 13, characterized in that it has a A cutting blade according to any one of claims 5 to 14, characterized in that said beveled region (8) is molded into said second material (19). Depilation, comprising a cutting blade according to any one of claims 1-15.

Images